title: Multifunctional porous titanium oxide coating with apatite forming ability and photocatalytic activity on a titanium substrate formed by plasma electrolytic oxidation.
abstract: Plasma electrolytic oxidation (PEO) was used to make a multifunctional porous titanium oxide (TiO2) coating on a titanium substrate. The key finding of this study is that a highly crystalline TiO2 coating can be made by performing the PEO in an ammonium acetate (CH3COONH4) solution; the PEO coating was formed by alternating between rapid heating by spark discharges and quenching in the solution. The high crystallinity of the TiO2 led to the surface having multiple functions, including apatite forming ability and photocatalytic activity. Hydroxyapatite formed on the PEO coating when it was soaked in simulated body fluid. The good apatite forming ability can be attributed to the high density of hydroxyl groups on the anatase and rutile phases in the coating. The degradation of methylene blue under ultraviolet radiation indicated that the coating had high photocatalytic activity.
authors.affiliation: Secure Materials Center, Materials and Structures Laboratory, Tokyo Institute of Technology, R3-24, 4259 Nagatsuta, Midori, Yokohama 226-8503, Japan. Electronic address: akatsu.t.aa@m.titech.ac.jp.
authors.forename: T
authors.initials: T
authors.lastname: Akatsu
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada
authors.forename: Y
authors.initials: Y
authors.lastname: Hoshikawa
authors.forename: T
authors.initials: T
authors.lastname: Onoki
authors.forename: Y
authors.initials: Y
authors.lastname: Shinoda
authors.forename: F
authors.initials: F
authors.lastname: Wakai
mesh_terms: D000085:Acetates / Q000737:chemistry; D001031:Apatites / Q000737:chemistry*; D002384:Catalysis; D004573:Electrolytes / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry; D010084:Oxidation-Reduction; D016062:Porosity; D014025:Titanium / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D000085:Acetates; D001031:Apatites; D004573:Electrolytes; C009495:titanium dioxide; D014025:Titanium; C018824:ammonium acetate; D008751:Methylene Blue
keywords: Apatite forming ability; Photocatalysis; Plasma electrolytic oxidation; Titanium dioxide